The present invention relates to an electronic apparatus, such as, a personal computer and/or a server, etc., and in particular, it relates to a liquid cooling system, being enable to cool a semiconductor integrated circuit element mounted within an inside thereof, as being a heat-generating element, with using a liquid coolant, effectively.
In general, a heat-generating element, for example, a semiconductor integrated circuit element, which generates heat within the electronic apparatus, such as, a personal computer of desk-top type or notebook type, or a server, etc., and in particular, a CPU (i.e., a central processing unit), representatively, it needs a cooling for maintaining the normal operation thereof. Conventionally, for that reason, it is general that such cooling is achieved with using a heat-transfer body, which is built up with fins called by a heat sink, to be a unit, and also a fan for sending a cooling wind upon the surface thereof. However, in recent years, small-sizing and high-integration on the semiconductor integrated circuit element, as being the heat-generating element, causes a problem, such as, localizing portions of generating the heat within the heat-generating element. For that reason, in the place of the conventional cooling system of air-cooling type, attentions are paid upon a cooling system of liquid-type, with using a coolant therein, such as, a water or the like, for example, having a high cooling efficiency.
Namely, with the liquid-type cooling system of high cooling efficiency, which is applied in the personal computer and/or the server, etc., as is already known in the following patent documents, for example, in general, a member, being so-called by a heat-receiving (or cooling) jacket, is directly mounted upon the surface of the CPU, being the heat-generating body, while a liquid-like coolant is communicated within a flow passage, which is formed within an inside of that heat-receiving jacket; i.e., transmitting the heat generated from the CPU into the coolant flowing within the jacket mentioned above, thereby cooling down the heat-generating body with high efficiency. Further, within such the cooling system of liquid-cooling type, in general, there is built up a heat cycle, while applying the heat-receiving jacket as a heat-receiving portion thereof, and in more details thereof, comprising a circulation pump for circulating the liquid coolant within the cycle, so-called a radiator, being a heat radiation portion for radiating the heat of the liquid coolant into an outside thereof, and further a coolant tank, being provided in a portion of the cycle if necessary, and wherein those are connected in the structure thereof through tubes, being made of a metal, or an elastic material, such as, rubber, etc., for example.    Patent Document 1: Japanese Patent Laying-Open No. 2003-304086 (2003);    Patent Document 2: Japanese Patent Laying-Open No. 2003-022148 (2003);    Patent Document 3: Japanese Patent Laying-Open No. 2002-182797 (2002);    Patent Document 4: Japanese Patent Laying-Open No. 2002-189535 (2002);    Patent Document 5: Japanese Patent Laying-Open No. 2002-189536 (2002); and    Patent Document 6: Japanese Patent Laying-Open No. 2002-188876 (2002).
On the other hand, generally within such the cooling system relating to the conventional arts mentioned above, so-called a centrifugal pump is applied, widely, to be the circulation pump for driving the liquid coolant, which is provided in a portion of that heat cycle, due to the following reasons; i.e., a flow rate obtained therefrom is relatively large in an amount thereof, and noises are small, which are caused due to contact, etc. With such the circulation pump of applying such the centrifugal pump therein, however there is a necessity of providing an electric motor, separately, for the purpose of rotationally driving such the pump, although being also true for the case of applying a pump of other types therein; and for this reason, the circulation pump as whole comes to be relatively large in the sizes thereof.
On the other hand, in recent years, it is of course for the electronic apparatuses, including, such as, the personal computer of the desktop type and the server, etc., that demand or requirement for small-sizing thereof rises up to be higher and higher, in particular, upon the personal computer of the notebook type, for the purpose of improving the portability thereof. For this reason, under the present situation, it is not always possible to deal with such the requirement with the circulation pump of the conventional arts mentioned above. In addition thereto, further there is also demand or requirement increasing up, for lowering the noises generated during when such the electronic apparatus is operating.